An Oklahoma volunteer reserve sheriff deputy who said he mistakenly shot an unarmed black man with his Taser gun was convicted of second-degree manslaughter on Wednesday. Robert Bates, now an ex-deputy for the Tulsa County Sheriff's Office, said he mistook his gun for his Taser stun gun when he shot and killed Eric Courtney Harris. Bates fatally shot Harris, who was tackled and was being held down on the ground. A jury recommended four years in prison for the 74-year-old, the maximum possible sentence. Preliminary sentencing is slated for May 31.